The present invention relates generally to thermoplastic thermoformable packaging film suitable for cook-in packaging and their use. More particularly, the present invention provides a cook-in package including a printed label within the layers of the film structure. The printed label is capable of being formed, shrunk and cut, while still retaining its readable qualities while being resistant to abuse and some distortion.
Many food products during preprocessing are stuffed into a casing and then placed in a heated medium, such as a hot water bath, for cook-in to produce a precooked encased food product. The term "cook-in" conventionally refers to cooking of a food product while contained in a package. Alternatively, the package may be a heat-shrinkable bag that shrinks tightly about a contained food product upon initial exposure to cook-in conditions.
The term "cook-in package" refers to packaging material structurally capable of withstanding exposure to cook-in, time-temperature conditions, while containing a food product. Cook-in, time-temperature conditions typically imply a long slow cook. For example, the product may be steam cooked at 150.degree. to 190.degree. F. for 5-7 hours. Under such conditions, a packaging material properly characterized as cook-in will maintain heat seal integrity and will be delamination resistant.
A wide variety of heat-shrinkable, multi-layer plastic films are useful as packaging materials for processed meat or like food. Among the variety of packaging containers, one class of container structures involves the use of a formable web member that is preformed into a desired tray configuration, pocket, or the like before being filled with food product and sealed with a (usually non-formable) lid web member. The web structures employed in this class of container structures are typically in the form of multi-layered webs or laminates. Each layer individually serves one or more functions and coact together to provide a container wall structure that protects the food product from the environment in a package system. Furthermore, such packages provide thermal stability, meat adherency and heat-shrink characteristics suitable for the form, fill and cook operations.
Commercial procedures being used to package food products require at least two bags if they are to contain printed information, one being an unprinted forming film and the other being a printed shrink bag. In one class of structures, the unprinted forming package generally consists of a forming web and a non-forming web. In operation, the forming web is heated and formed into a pocket on the packaging machine. The food product, such as turkey, is placed into the pocket, the web is advanced and the non-forming web is sealed onto the flanges of the formed web. The packaged turkey is then put through a hot water shrink machine to tighten the package around the product. The packaged food product is then steam cooked at about 170-190.degree. F. for 5-7 hours.
After the cooking process is completed, the finished cooked product, in the unprinted forming package, goes through another operation for "retailing." In particular, the package containing the finished cooked food product is placed into a printed shrink bag, the top sealed and put through a hot water shrink bath or tunnel for shrinking the bag around the packaged food product. This current practice of "over-bagging" is a complete second operation for the finished product and very costly.
In an effort to eliminate the additional costs of over-bagging, attempts have been made to produce some type of printed structure. However, prior attempts to provide printed forming films have proven unsatisfactory. Printed forming films have been produced with a solid color background or a continuous design, such as cross-hatch, or a word or words that provide a design on the formed film. However, in all cases in the past, the designs have become distorted because the unoriented printed substrate cannot be formed within the consistency or balance that allows a printed label to be legible. The complete labels have therefore not been able to be printed on the flexible thermoformed cook-in films.
Therefore, a need exists for a cook-in package that includes a printed label, thereby eliminating the need for dual packaging.